Gershon v. Back, 346 Conn. 181

Background

Parties entered a prenuptial agreement; during New York divorce they executed a separation agreement that superseded the prenup and resolved property and support rights.
The separation agreement: (a) contained a New York choice‑of‑law clause; (b) expressly provided it "survives" and "shall not be merged" into any divorce judgment; and (c) incorporated New York’s plenary action rule (requiring a separate contract action to challenge an unmerged agreement).
The New York court entered a final judgment of divorce that incorporated but did not merge the separation agreement.
Plaintiff later moved to Connecticut, registered the New York judgment under Conn. Gen. Stat. § 46b‑71, and sought to open and set aside the judgment in Connecticut Superior Court alleging defendant fraudulently misstated income.
The Superior Court applied New York law, held the separation agreement was unmerged and thus challengeable only by a New York plenary action, and dismissed the motion for lack of subject matter jurisdiction.
The Appellate Court agreed the plenary action rule is substantive for choice‑of‑law purposes but held Connecticut had jurisdiction under § 46b‑71(b) and that the motion should have been denied rather than dismissed; the Supreme Court affirmed the Appellate Court.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether New York’s plenary action rule is procedural or substantive for choice‑of‑law when a foreign matrimonial judgment is registered in Connecticut	Gershon: the rule is procedural — it prescribes the means to vindicate preexisting contractual rights and thus Connecticut procedure should apply	Back: the rule is substantive — it limits the right to challenge an unmerged separation agreement and creates vested contractual rights independent of the divorce judgment	The rule is substantive under Restatement §122 factors (party expectations, effect on outcome, precedent, and forum burden) and thus New York substantive law governs the availability of postjudgment relief while Connecticut procedure applies generally.
Whether the Connecticut court lacked subject matter jurisdiction and therefore should have dismissed the motion	Gershon: Connecticut procedural law should govern; dismissal was improper and §46b‑71(b) gives Connecticut power to consider post‑registration motions	Back: New York rule controls outcome; challenge requires a plenary contract action, not a motion to open	Appellate Court and Supreme Court: Connecticut has jurisdiction to hear the motion under §46b‑71(b); but because New York substantive law controls, the motion should have been denied on the merits rather than dismissed for lack of jurisdiction.
Whether Baxter and similar Connecticut precedent force characterizing the plenary action rule as procedural	Gershon: Baxter suggests rules that only affect remedial means are procedural where the underlying right existed at common law	Back: Baxter is inapposite; the plenary action rule is not a statute of repose/limitations and is an entrenched common‑law limitation on the right to challenge an unmerged agreement	Court: Baxter’s statute‑of‑limitations analysis does not apply; the plenary action rule is an independent, substantive limitation on the right to attack an unmerged separation agreement.

Key Cases Cited

Reclaimant Corp. v. Deutsch, 332 Conn. 590 (2019) (sets out forum procedure vs. foreign substantive law framework and cites Restatement §122 guidance)
Baxter v. Sturm, Ruger & Co., 230 Conn. 335 (1994) (statute‑of‑repose analysis discussed and distinguished)
Weber v. U.S. Sterling Securities, Inc., 282 Conn. 722 (2007) (defines substance vs. procedure distinction)
Kleila v. Kleila, 50 N.Y.2d 277 (1980) (New York rule: unmerged separation agreement is independent contract; challenge by plenary action)
Teitelbaum Holdings, Ltd. v. Gold, 48 N.Y.2d 51 (1979) (New York public policy favoring finality of judgments)
Lacks v. Lacks, 41 N.Y.2d 71 (1976) (distinguishes court competence from substantive elements of claims)
Yonkers Fur Dressing Co. v. Royal Ins. Co., 247 N.Y. 435 (1928) (early articulation that compromise connected to concluded action must be challenged by plenary suit)